643900434 has 8 divisors (see below), whose sum is σ = 1287800880. Its totient is φ = 214633476.

The previous prime is 643900379. The next prime is 643900507. The reversal of 643900434 is 434009346.

It is a sphenic number, since it is the product of 3 distinct primes.

643900434 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 643900395 and 643900404.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53658364 + ... + 53658375.

It is an arithmetic number, because the mean of its divisors is an integer number (160975110).

Almost surely, 2^643900434 is an apocalyptic number.

643900434 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643900434 is a wasteful number, since it uses less digits than its factorization.

643900434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107316744.

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 643900434 is about 25375.1932800521. The cubic root of 643900434 is about 863.5210045377.

The spelling of 643900434 in words is "six hundred forty-three million, nine hundred thousand, four hundred thirty-four".